• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.129-134
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• 2023

Although the use of batteries is rapidly increasing worldwide to improve carbon neutrality and energy efficiency, performance degradation due to the increase in the number of uses is inevitable as it is a finite resource that can be applied according to capacity and specifications. Deterioration and failure of batteries are recognized as important problems in various applications using batteries, including electric vehicles. In order to solve these problems, a diagnostic technology capable of accurately predicting battery life and grasping state information is required, but it is difficult in a non-linear form due to internal structure or chemical change. In this paper, the factors that generally cause battery performance change are directly applied to check whether there are external changes and impedance changes in the battery, and to analyze whether they affect battery life. Impedance change trends and result values were confirmed using a universal impedance spectroscopy method and a self-developed internal impedance measurement method. The results did not significantly affect the impedance change trend. It was confirmed that the increase in the number of times of battery use was prominent in the impedance change trend.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.345-363
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• 2003

From the General Circulation Models(GCMs), it is known that the increases of concentrations of greenhouse gases will have significant implications for climate change in global and regional scales. The GCM has an uncertainty in analyzing the meteorologic processes at individual sites and so the 'downscaling' techniques are used to bridge the spatial and temporal resolution gaps between what, at present, climate modellers can provide and what impact assessors require. This paper describes a method for assessing local climate change impacts using a robust statistical downscaling technique. The method facilitates the rapid development of multiple, low-cost, single-site scenarios of daily surface weather variables under current and future regional climate forcing. The construction of climate change scenarios based on spatial regression(transfer function) downscaling and on the use of a local stochastic weather generator is described. Regression downscaling translates the GCM grid-box predictions with coarse resolution of climate change to site-specific values and the values were then used to perturb the parameters of the stochastic weather generator in order to simulate site-specific daily weather values. In this study, the global climate change scenarios are constructed using the YONU GCM control run and transient experiments.

• Environmental and Resource Economics Review
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• v.24 no.2
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• pp.343-363
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• 2015

This study is to analyze the effects of climate change on national total factor productivity. Changes in temperature and rainfalls which are the representative climate variables are used as main factors to measure climate change. Not only average values of the variables but those highest values are used as independent variables in the model, in order to consider the characteristic pattern of recent climate change, the high volatilities. The OLS results are corresponding to previous literature that average temperature has a negative relationship with productivities while average rainfalls have a positive relationship. However, the results of panel analysis contradict the argument of the negative relationship between average temperature and productivities since human beings can adapt the climate change. Therefore adaptation capacity is important to forecast the effects of climate changes on economies.

• Atmosphere
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• v.33 no.1
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• pp.1-20
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• 2023

Holding the longest observation data from April 1904, Busan is one of the essential points to understand the climate variability of the Korean Peninsula without missing data since implementing the modern weather observation of the South Korea. Busan is featured by coastal areas and affected by various climate factors and fluctuations. This study aims to investigate climate variability and changes in climatic variables, extremes, and several weather indexes. The statistically significant change points in daily mean rainfall intensity and temperature were found in 1964 and 1965. Based on the change point detection, 117 years were divided into two periods for daily mean rainfall intensity and temperature, respectively. In the long-term temperature analysis of Busan, the increasing trend of the daily maximum temperature during the period of 1965~2021 was larger than the daily mean temperature and the daily minimum temperature. Applying Ensemble Empirical Mode Decomposition, daily maximum temperature is largely affected by the decadal variability compared to the daily mean and minimum temperature. In addition, the trend of daily precipitation intensity from 1964~2021 shows a value of about 0.50 mm day^-1, suggesting that the rainfall intensity has increased compared to the preceding period. The results in extremes analysis demonstrate that return values of both extreme temperatures and precipitation show higher values in the latter than in the former period, indicating that the intensity of the current extreme phenomenon increases. For Wet-Bulb Globe Temperature (effective humidity), increasing (decreasing) trend is significant in Busan with the second (third)-largest change among four stations.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.357-371
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• 2016

Buildings in the city acts as a cause of distorted wind direction, wind speed, causing the stagnation of the air flow. In the recent trend of climate change can not but consider the temperature rise of the urbanization. This study was aimed to analyze the thermal comfort of planetary boundary layer in different artificial constructions areas which has a direct impact on urban climate, and estimating the warming phenomena. Envi-met model was used to consider the urban structure associated with urban growth in order to precisely determine the impact of the building on the city weather condition. The analyzed values of thermal comfort index were temperature, wind speed, horizontal and vertical turbulent diffusivity. In particular, analysis of the PPD(Predicted Percentage of Dissatisfied) represents the human thermal comfort. In this study, by adjusting the arrangement and proportion of the top floor building in the urban it was found that the inflow of the fresh air and cooling can be derived low PPD. Vertical heat flux amount of the city caused by climate change was a factor to form a high potential temperature in the city and the accumulation of cold air does not appear near the surface. Based on this, to make the city effectively respond to climate change may require a long-term restructuring of urban spatial structure and density management.

• Journal of Chest Surgery
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• v.23 no.5
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• pp.854-863
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• 1990

Since the open heart surgery was performed, various kinds of problem concerning the extracorporeal circulation[EGG] have been known. The author investigated the changes of serum potassium ion before and after ECC among the 102 patients including 63 adults and 39 children who underwent open heart surgery from April 19S6 to February 1990 in Chung-Ang University Hospital. The mean values of potassium ion before and after ECC were analyzed according to the influencing factors such as priming solution, aortic cross clamping time, the underlying disease, the type of oxygenator and the amount of cardioplegic solution. The results were as follows: l. In the aspect of congenital and acquired heart disease groups, the mean values of serum potassium ion[Mean\ulcornerS.D.] before and after ECC revealed a significant change only in the acquired heart disease group[congenital; 3.87$\pm$0.48mEq /L vs. 4.05$\pm$0.73mEq /L, P>0.05, acquired: 4.40 $\pm$0.98mEq /L vs. 4.11$\pm$0.52mEq /L, P<0.05]. Between the two groups, the changes of the mean values of serum potassium ion before and after ECC were significant[P<0.05]. But all values were within normal limits. 2. In the aspect of the aortic cross clamping time[ACCT], in the groups of less or more than 120 minutes, the mean values of serum potassium ion before and after ECC revealed no significant change[less than 120 min; 3.97+-0.64mEq /L vs. 3.99+0.67mEq /L, P>0.05, more than 120 min; 4.34+0.82mEq /L vs. 4.27+0.62mEq /L, P>0.05], and The changes of mean values of serum potassium ion between the two groups were not significant[P>0.05]. 3. In both membrane and bubble oxygenator groups, the mean values of serum potassium ion before and after ECC did not reveal a significant difference respectively [membrane; 4.74 +1.40mEq /L vs. 4.28+0.3lmEq /L, P>0.05, bubble; 4.02 +0.60mEq /L vs. 4.05 L0.68mEq/L, P>0.05], and no differences between the membrane and bubble oxygenator groups[P >0.05]. 4. In the groups of membrane and bubble oxygenator in the cases of ACCT more than 120 minutes, the mean values of serum potassium ion before and after ECC did not reveal a significant difference respectively[membrane; 4.36$\pm$0.85mEq /L vs. 4.37$\pm$0.26mEq /L, P>0.05, bubble; 4.30 $\pm$0.80mEq/L vs. 4.23$\pm$0.67mEq/L, P>0.05], and no differences between the two groups[P>0.05]. 5. In spite of increased amount of cold potassium cardioplegic solution, the mean values of serum potassium ion before ECC were similar to those of serum potassium ion after ECC[less than 20ml /kg

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.2
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• pp.166-172
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• 1997

Background : For example, aerodynamic study, vibratory study, acoustic study, neuro-muscular test and psychoacoustic evaluation, a number of objective methods are now available for assessing pathologic voice change. They help to differentiate pathologic condition from normal condition and to monitor pathologic and aging change. These laboratory analyses are used commonly to monitor speech therapy and to follow a patient's recovery after surgery. Objectives : We investigated the values of jitter, shimmer and NNE of normal person and hoarseness patients in Korea. The values of Jitter and shimmer might be meaningful parameters distinguishing pathologic vibration from normal and recovery after surgery. Materials and Methods : Statistical significance between normal control and 48 subjects taken microlaryngeal surgery were compared with Dr. speech science program that is computerized system for acoustic analysis of voice production employed to determine vocal characteristics of pitch perturbation(jitter) and amplitude perturbation(shimmer). Results : The mean normal values of jitter and shimmer were 0.226${\pm}$0.110(%), 2.200${\pm}$0.421(%) in male and 0.164${\pm}$0.060(%), 2.063 ${\pm}$0.575(%) in female. In patients with vocal nodule, the preoperative and postoperative values of jitter and shimmer were valueless. In patients with vocal polyps, the preoperative and postoperative values of jitter and shimmer were valuable. Conclusion : Dr. speech science program was effective to monitor laryngeal disease and aging changes.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.157-160
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• 2003

In this paper. we propose a simple and effective video scene change detection algorithm using a 3-D DCT. The 3-D DCT that we employ is a 2$\times$2$\times$2 DCT has simple computations composed only of adding and shifting operations. The simple average values of multiresolution represented video using the 2$\times$2$\times$2 DCT are used as a detection feature vector.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.197-204
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• 2018

Multiple myeloma (MM) is the leading cause of death among hematologic neoplasms. Recently, microRNA has been reported to be useful in the diagnosis of multiple myeloma. This study examined whether miR-221 could be used as a diagnostic marker for multiple myeloma. The study was performed on 20 patients with multiple myeloma without any other hematological diseases. MicroRNA extraction was performed using formalin-fixed paraffin-embedded (FFPE) tissues obtained from the bone marrow of patients with multiple myeloma. miR-15a, miR-16, miR-21, miR-181a, and miR-221 were selected as the microRNA target genes for multiple myeloma. The significance of microRNA was based on a fold change of <1.5. To quantify the fold changes, data normalized to the human gene, SNORD43, were used as the values of the patient group. Fold change values greater than 1.5 were defined as "overexpression", whereas values less than -1.5 were defined as "underexpression". Of note, 65.0% (13/20) of samples showed significant "overexpression" in the levels of miR-221 expression and plasma cells with a group of more and less than 30% in MM patients did not show any significance of plasma cell (P<0.05). The results of other studies showing a correlation between the expression of miR-221 and MM in Caucasians were confirmed. These results suggest that miR-221 may be a useful indicator for diagnosing patients with MM. In conclusion, miR-221 is useful in the diagnosis and determining the prognosis of multiple myeloma in Koreans.

• Journal of the Korean Applied Science and Technology
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• v.8 no.2
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• pp.105-114
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• 1991

In relation to the preparation of Langmuir-Blodgett thin film, four kinds of N-alkylpyridiniurn bromide were synthesized. The values of surface tensions of these materials, measured with a Traube stalagmometer, gave the relationship between the critical micells hydrophobic radical and between CMC and temperature. Values of thermodynamic properties(${\Delta}H^0_m,\;{\Delta}S^0_m,\;{\Delta}G^0_m,$) for the formatoin of micelle were also obtained. Experiments gave the following results; at the temperature range between 40 and 60$^{\circ}C, CMC of Hexadecyl-, Octadecyl-, Eicosyl-, and Docosyl-Pyridinium Bromide were $7.64{\times}10^{-4}{\sim}9.13{\times}10^{-4},\;3.85{\times}10^{-4}{\sim}4.60{\times}10^{-4},\;2.00{\times}10^{-4}{\sim}2.39{\times}10^{-4},\;and\;1.07{\times}10^{-4}{\sim}1.28{\times}10^{-4}$ mol/l, respectively. Surface tension, ${\Gamma}_{CMC}$, of those were 33.49${\sim}$36.00, 34.78${\sim}$37.61, 35.49${\sim}$37.61 and 38.76${\sim}$55.80 dyne/cm, respectively, The relationship between CMC and the mumber of carbon atoms in the hydrophobic radical, N was expressed as follows : Log(CMC)=A-BN where A and B are constants. At the temperature range between 40 and 60$^{\circ}C$, the change of Gibbs evergy (${\Delta}G_m$) for one methylene group ($-CH_2-$) were -0.65RT, respectively, The minus values of enthalpy change (${\Delta}H_m$) suggest that the formation of micelle is exothermic. Additionally, the overall increase in the entropy change (${\Delta}S_m$) with respect to the temperature increase suggests that the formation of micelle is attained by a exothermic enthalpy directed process.